add code for presence detection

PresenceDetection.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "BleScanner.h"
+#include "BleInterfaces.h"
+
+struct PdDevice
+{
+    char address[18] = {0};
+    char name[30] = {0};
+    unsigned long timestamp;
+};
+
+class PresenceDetection : public BLEScannerSubscriber
+{
+public:
+    PresenceDetection(BleScanner* bleScanner);
+    virtual ~PresenceDetection();
+
+    void initialize();
+    void update();
+
+    void onResult(NimBLEAdvertisedDevice* advertisedDevice) override;
+
+private:
+    BleScanner* _bleScanner;
+    std::map<long long, PdDevice> _devices;
+    uint _timeout = 20000;
+};